I'm a frustrated mother of 6 year old here! I'm ADD but he's got ADD on steroids! Seriously. Any symptoms I had as a girl, he's got them tenfold as a little boy. It is frustrating, especially in our case, since it's the ADD leading the ADD - a recipe for a lot of forgotten tasks (and sweatshirts).

The doctor will likely help his self esteem, not hurt it. When he realizes the reason he has these behaviours is not because he's lazy, or stupid, or any other negative thing. It's simply a chemical imbalance that can be corrected with meds or behaviour therapy. I bet he'll be relieved to know this.